Reiman Gardens Water Mystery
Welcome to Reiman Gardens. For the next two hours, you’re going to be doing real science in a real botanical garden — testing, observing, and figuring out what’s going on outside.
Before we get into it, you’re going to meet your team. For each question, walk to the corner of the room that matches your answer. You’ll have about 30 seconds in each corner to introduce yourself and say why you picked it — then we move to the next question.
- Corner A: The Butterfly Wing — live tropical butterflies indoors
- Corner B: The Rose Collection — thousands of roses in bloom
- Corner C: The Pollinator Garden — bees, butterflies, native plants
- Corner D: The Big & Small exhibit — giant outdoor flower sculptures
- Corner A: Run a test to measure what’s different
- Corner B: Walk the area and look for clues
- Corner C: Ask someone who knows the area
- Corner D: Look up whether this has happened before
- Corner A: Water & chemistry — testing what’s in liquids
- Corner B: Plants & ecosystems — how living systems connect
- Corner C: Insects & pollinators — small creatures, big impact
- Corner D: Soil & agriculture — growing food and supporting land
Notice where you ended up. Some of you are going to think like investigators today. Some like field scientists. Some like chemists. You’ll need all of it.
The Big and Small exhibit just opened. Record crowds are streaming through the gardens. Behind the scenes, the Reiman Gardens horticulture team is working overtime to keep everything looking perfect for visitors — and they’ve just hit a problem they can’t explain.
Three things have gone wrong in the past two weeks:
- A patch of roses near the main visitor pathway has started yellowing at the edges.
- The bees and butterflies that usually crowd the Pollinator Garden have gone quiet.
- The fountain at the entrance has looked cloudy for days.
The head horticulturalist suspects water chemistry. Staff have collected 6 water samples from around the gardens — every place a watering system, treatment tank, runoff path, or cleaning operation could be affecting plant or pollinator health. They’ve handed you the case. Find the source — or rule it out — before it spreads.
Your tool: red cabbage juice. It’s a natural pH indicator that shifts color from red (acidic) through purple (neutral) to blue, green, and yellow (basic). Plants, soil microbes, and pollinators all need water within a specific pH range. If one of these samples is far outside that range — and flowing somewhere it shouldn’t — you can find it.
Each pair has a sealed bag of chopped red cabbage at their workstation.
Seal the bag tightly and crush the cabbage with your hands until the juice releases and the liquid inside turns deep purple. This is your pH indicator — same chemistry as the test strips a real chemist uses in a lab, just dyed by red cabbage instead of synthetic dye.
Set the bag aside. You’ll come back to it after you’ve collected your samples.
Six samples are pre-filled in numbered bottles at the central sample table. Each one came from somewhere staff thought worth checking:
- Pollinator Garden Sprinkler — water from the irrigation system that keeps the bee and butterfly habitat alive.
- Pathway Weed Treatment Spray — runoff from the organic spray staff use to kill weeds along visitor walkways.
- Conservatory Window Washdown — wastewater from cleaning the butterfly conservatory’s glass walls.
- Concession Area Runoff — liquid that drained out from under the visitor refreshment area.
- Water Feature Conditioning Tank — treated water from the entrance fountain.
- Greenhouse Sanitation Rinse — runoff from cleaning tools and benches in the greenhouse.
Testing procedure:
- Bring your stand of 6 empty test tubes to the central sample table.
- Each numbered bottle has its own dedicated dropper. Never move a dropper from one bottle to another — that’s how samples get contaminated and ruined for the next team.
- Use bottle 1’s dropper to fill test tube 1 about ¼ full. Bottle 2’s dropper for tube 2. Repeat for all six.
- Bring your filled stand back to your workstation.
- Add several drops of cabbage juice to each test tube. Use a fresh dropper for each tube so you don’t carry colors backwards.
- Watch the color change immediately. Compare each tube to the cabbage juice color chart on your table.
- Dip a pH strip into each tube. The cabbage gives you the category; the strip gives you the number.
- Which water source has the most extreme pH reading?
- Is it acidic or basic — and what does that mean for plants, soil, or pollinators nearby?
- What could be causing the problem at that source?
- What should the gardens team do next to protect the affected area?
- Which water source looks healthiest for plants and pollinators? What’s your evidence?
- Why might compost drainage have a different pH than tap water?
- What might happen to roots, soil microbes, or insects if water in the garden becomes too acidic or too basic?
Head into the gardens with your team. You’re looking for physical evidence in the real space that matches what your samples showed.
Walk through the area where your most extreme sample was collected. Look for:
- Where water collects after rain — low spots, puddled areas, soggy mulch
- Where runoff flows (downhill paths, gravel lines, drainage cuts)
- Plants that look healthy vs. plants that look stressed
- Pollinator activity — or the lack of it
- Anything that could be an acid or base source: compost piles, mulch beds, cleaning supplies, fertilizer storage, salt-treated walkways
On your 📋 Reiman Gardens Field Notebook, note one piece of physical evidence that supports your hypothesis — or one that complicates it. Real engineers care about both.
Environmental chemists and water quality engineers test water sources every day — at farms, gardens, rivers, drinking water plants, and wastewater facilities. They’re the reason your tap water is safe to drink and the reason farmers know when their soil needs adjusting. The Iowa Department of Natural Resources tests rivers and lakes across the state for pH every month for exactly this reason — to catch problems before they spread. The cabbage juice you used today is a low-tech version of the same chemistry happening in environmental labs across Iowa right now.
Each team has 90 seconds to present. Bring your 📋 Reiman Gardens Field Notebook — your data is your evidence.
- Which water source is your suspect?
- What evidence supports your claim? (color observed + pH number + field observations)
- What should Reiman Gardens do next to protect the affected area?